Comment 2 for bug 1867335

Thank you for taking the time to report this bug and helping to make Ubuntu better.

Bug reporting is about finding & fixing problems thus preventing future users from hitting the same bug.

Your statement '"apt-cache policy pkgname" this does not work' seems to imply you didn't change pkgname with the name of the package you wanted to search for; as there are no packages named "pkgname" (https://packages.ubuntu.com/search?suite=all&searchon=names&keywords=pkgname) so you should have got a message like "N: Unable to locate package pkgname".

I suspect a Support site would be more appropriate, eg. https://answers.launchpad.net/ubuntu. You can also find help with your problem in the support forum of your local Ubuntu community http://loco.ubuntu.com/ or asking at https://askubuntu.com or https://ubuntuforums.org, or for more support options please look at https://discourse.ubuntu.com/t/community-support/709